Special Coverage

New factors suspects in MRLS

LEXINGTON, Ky. - A new study of last spring's abortion wave known as mare reproductive loss syndrome suggests some new factors that might have predisposed mares to the syndrome.

Researchers funded by the state of Kentucky and the Grayson-Jockey Club Research Foundation announced Wednesday that new factors included the presence of elk or deer at affected farms during the year preceding the outbreak, and an increased amount of white clover in pastures in the four weeks before abortion.

The study also indicated that heavy caterpillar infestation, feeding hay in pastures in a four-week period before the abortions, and a history of abortion in the previous five years also increased mares' risk for MRLS last year, when an estimated 2,500 mares were stricken.

Dr. Noah Cohen of Texas A&M University, one of the researchers who led the study, which compared more than 100 characteristics of mares who experienced MRLS in 2001 with those who bred successfully the previous year, said that "there were unusual conditions influencing the pastures during 2001," including the rise in white clover and caterpillars.